WO1991004098A1 - Feeder of a counter jet pulverizer - Google Patents

Feeder of a counter jet pulverizer Download PDF

Info

Publication number
WO1991004098A1
WO1991004098A1 PCT/FI1990/000213 FI9000213W WO9104098A1 WO 1991004098 A1 WO1991004098 A1 WO 1991004098A1 FI 9000213 W FI9000213 W FI 9000213W WO 9104098 A1 WO9104098 A1 WO 9104098A1
Authority
WO
WIPO (PCT)
Prior art keywords
feeder
compartment
outlet
working
gas
Prior art date
Application number
PCT/FI1990/000213
Other languages
French (fr)
Inventor
Kyösti KOHO
Markku PERÄKYLÄ
Original Assignee
Micro Milling Machines Oy
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Micro Milling Machines Oy filed Critical Micro Milling Machines Oy
Publication of WO1991004098A1 publication Critical patent/WO1991004098A1/en

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B02—CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
    • B02C—CRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN
    • B02C19/00—Other disintegrating devices or methods
    • B02C19/06—Jet mills
    • B02C19/065—Jet mills of the opposed-jet type

Definitions

  • the present invention relates to a feeder of a counter jet pulverizer comprising a feeding funnel or silo for the material to be pulverized, a compartment feeder ar ⁇ ranged in its outlet, the compartments of the compart ⁇ ment wheel of the feeder being by their circumferential dimensions considerably smaller than the diameter of the outlet of the compartment feeder, and a fluidizing space arranged on the outlet side of the compartment feeder for achieving in the pulverizing chamber a pressurized mate ⁇ rial-working-gas suspension to be accelerated via accele ⁇ rating nozzles.
  • a valve feeder of a conventional pressure chamber grinder equipment has proven to be a too expensive solu ⁇ tion, also limiting the pulverizing capacity.
  • the purpose of this invention is to eliminate the above- mentioned problems, which is achieved in such a way that the diameter of the outlet of the compartment feeder in the rotational direction of the compartment wheel ex ⁇ pands at least initially mainly angularly.
  • Fig. 1 is an example of a counter jet pulverizing equip ⁇ ment, on which a feeder according to the invention is mounted,
  • Fig. 2 shows a section along the line A-A of Fig. 1,
  • Fig. 3 is another example of a counter jet pulverizing equipment, on which a feeder according to the in ⁇ vention is mounted,
  • Fig. 4 is a side view of an example of a counter jet pul ⁇ verizing equipment, in which a modified feeder ac ⁇ cording to the invention is mounted,
  • Fig. 5 shows the machinery of Fig. 4 seen from above
  • Fig. 6 shows a section along the line A-A of Fig. 4,
  • Fig. 7 shows another modified example of the feeder accor ⁇ ding to the invention.
  • a counter jet pulverizing equipment in which a feeder ac ⁇ cording to the invention is used, comprises a feeding fun ⁇ nel or silo 1 for the material to be pulverized, a com ⁇ partment feeder 2 arranged in its outlet, the compartments of the compartment wheel 9 of the feeder being by their circumferential dimensions considerably smaller than the diameter of the outlet 8 of the compartment feeder 2, and a fluidizing space 3 arranged on the outlet side of the compartment feeder for achieving in the pulverizing cham ⁇ ber 5 a pressurized material-working-gas suspension to be accelerated via accelerating nozzles 5.
  • the working gas is supplied from a pressure gas source 6, as from a pneumatic compressor along a gas pipe 7 to the fluidizing space 3, wherein the material to be pulverized is admixed in the working gas flow and accelerated by means of an over ⁇ pressure prevailing in the fluidizing space via the acce ⁇ lerating nozzles 5 to the pulverizing chamber 4, whereby material particles emerging from the opposite nozzles 5 collide with each other in the center section of the pul ⁇ verizing chamber 4 and pulverize.
  • a good pulverizing ef ⁇ fect requires that the material-working-gas jets emerging from the opposite accelerating nozzles be both by their flow rate and solids content of the same size and cons ⁇ tant.
  • the cross-section of the outlet 8 of the compartment feeder is designed in such a way that it in the rotational direction of the compartment wheel 9 at least initially mainly angularly expands, as indicated in Fig. 2.
  • the idea is based on the fact that the emptying of the compartments alternately coming to the outlet 8 is prolonged in such a way that the emptying starts at the middle of the compartment and transfers uni ⁇ formly along with the expansion of the outlet toward both ends of the compartments, and before the preceding com ⁇ partment has totally emptied, the emptying of the next compartment starts so that the material supply to the fluidizing space 3 is as uniform as possible.
  • the side surfaces 10 limiting the angularly expanding portion of the outlet 8 of the compartment feeder are by their cross-section convex toward the outlet, which form even better ensures a uniform material supply.
  • each accelerating nozzle 5 of the counter jet pulverizer is furnished with its own compartment feeder 2 feeding the material to be pulverized and its own fluidizing space 3, into which wor- king gas is potentially supplied from its own pneumatic compressor 6.
  • the manufacturing costs of such a solution are relatively high and the pulverizing occurrence itself is not easily controllable, if abrupt changes occur in the use of the compressors and/or compartment feeders.
  • the equipment comprises only one compressor 6 and one compartment feeder 2 and a fluidizing space 3, whereby the outlet pipe 11 of the fluidizing space 3 terminates at a bisecting device 12, wherein the material-working-gas suspension divides into two equivalent partial flows entering the pulverizing chamber via their own accelerating nozzles 5.
  • the solution shown in this Fig. 3 ensures that no content and speed differences occur between the material-working-gas showers coming from the different accelerating nozzles 5.
  • a more simple and inexpensive pneumatic compressor can be utilized, if the outlet 8 of the compartment feeder 2 and the fluidizing space 3 connected therewith are divided by means of an in ⁇ termediate wall 13 into two sections of the same size and provided with their own gas inlet pipes 7 and their own material-working-gas-suspension outlet pipes 11 termina ⁇ ting at the pulverizing chamber 4 via the accelerating nozzle 5.
  • the pneumatic flow is in this case divided for example by means of a simple branch pipe or a bypass mani ⁇ fold 14 before its entry into the two parts of the fluidi ⁇ zing space 3, whereby the two material-working-gas- sus ⁇ pension partial flows can be led directly into their own accelerating nozzles 5, in which case the relatively high counter pressure occurring in the bisecting device can be eliminated.
  • a simple branch pipe or a bypass mani ⁇ fold 14 before its entry into the two parts of the fluidi ⁇ zing space 3
  • the two material-working-gas- sus ⁇ pension partial flows can be led directly into their own accelerating nozzles 5, in which case the relatively high counter pressure occurring in the bisecting device can be eliminated.
  • Such a construction is shown in Fig. 4 - 6.
  • one compartment feeder In low-pressure pulverizing, wherein a working-gas pres ⁇ sure of about max. 2 bar is used, one compartment feeder is enough to maintain a sufficient pulverizing pressure in the equipment.
  • two compartment feeders 2 arranged on top of each other and a pressure equalization chamber 15 combining them with each other must be used, whereby the pressure over each compartment feeder 2 does not exceed the maximum-pressure-difference duration of the feeder.
  • this medium-pressure pulveri ⁇ zing solution it is sufficient that the outlet of the lo ⁇ was compartment feeder 2 is designed so that it equalizes the inventive material flow.

Landscapes

  • Engineering & Computer Science (AREA)
  • Food Science & Technology (AREA)
  • Disintegrating Or Milling (AREA)

Abstract

The present invention relates to a feeder of a counter jet pulverizer comprising a feeding funnel or silo (1) for the material to be pulverized, a compartment feeder (2) arranged in its outlet, the compartments of the compartment wheel (9) of the feeder being by their circumferential dimensions considerably smaller than the diameter of the outlet (8) of the compartment feeder (2), and a fluidizing space (3) arranged on the outlet side of the compartment feeder (2) for achieving in the pulverizing chamber (4) a pressurized material-working-gas suspension to be accelerated via accelerating nozzles (5). The invention is characterized in that the cross-section of the outlet (8) of the compartment feeder (2) in the rotational direction of the compartment wheel (9) expands at least initially mainly angularly.

Description

Feeder of a counter jet pulverizer
The present invention relates to a feeder of a counter jet pulverizer comprising a feeding funnel or silo for the material to be pulverized, a compartment feeder ar¬ ranged in its outlet, the compartments of the compart¬ ment wheel of the feeder being by their circumferential dimensions considerably smaller than the diameter of the outlet of the compartment feeder, and a fluidizing space arranged on the outlet side of the compartment feeder for achieving in the pulverizing chamber a pressurized mate¬ rial-working-gas suspension to be accelerated via accele¬ rating nozzles.
Especially in such applications of the food industry, where no especially high pulverizing pressures are re¬ quired but a high pulverizing capacity is needed ins¬ tead, a valve feeder of a conventional pressure chamber grinder equipment has proven to be a too expensive solu¬ tion, also limiting the pulverizing capacity.
A counter jet pulverizer provided with a compartment fee¬ der has in fact been described in the US patent publi¬ cation no. 3,876,156, but an attempt has therein in no way been made to equalize the material loads falling by thrusts into the fluidizing or mixing space from the com¬ partments of the compartment feeder, which swing during the feeding of the material has a detrimental effect on the pulverizing occurrence itself.
The purpose of this invention is to eliminate the above- mentioned problems, which is achieved in such a way that the diameter of the outlet of the compartment feeder in the rotational direction of the compartment wheel ex¬ pands at least initially mainly angularly.
The other characteristics of , the invention become appa¬ rent on the basis of the enclosed patent claims 1 - 6. The invention is next described in more detail with re¬ ference to the accompanying drawing, in which
Fig. 1 is an example of a counter jet pulverizing equip¬ ment, on which a feeder according to the invention is mounted,
Fig. 2 shows a section along the line A-A of Fig. 1,
Fig. 3 is another example of a counter jet pulverizing equipment, on which a feeder according to the in¬ vention is mounted,
Fig. 4 is a side view of an example of a counter jet pul¬ verizing equipment, in which a modified feeder ac¬ cording to the invention is mounted,
Fig. 5 shows the machinery of Fig. 4 seen from above,
Fig. 6 shows a section along the line A-A of Fig. 4, and
Fig. 7 shows another modified example of the feeder accor¬ ding to the invention.
A counter jet pulverizing equipment, in which a feeder ac¬ cording to the invention is used, comprises a feeding fun¬ nel or silo 1 for the material to be pulverized, a com¬ partment feeder 2 arranged in its outlet, the compartments of the compartment wheel 9 of the feeder being by their circumferential dimensions considerably smaller than the diameter of the outlet 8 of the compartment feeder 2, and a fluidizing space 3 arranged on the outlet side of the compartment feeder for achieving in the pulverizing cham¬ ber 5 a pressurized material-working-gas suspension to be accelerated via accelerating nozzles 5. The working gas is supplied from a pressure gas source 6, as from a pneumatic compressor along a gas pipe 7 to the fluidizing space 3, wherein the material to be pulverized is admixed in the working gas flow and accelerated by means of an over¬ pressure prevailing in the fluidizing space via the acce¬ lerating nozzles 5 to the pulverizing chamber 4, whereby material particles emerging from the opposite nozzles 5 collide with each other in the center section of the pul¬ verizing chamber 4 and pulverize. A good pulverizing ef¬ fect requires that the material-working-gas jets emerging from the opposite accelerating nozzles be both by their flow rate and solids content of the same size and cons¬ tant. For equalizing the material flow coming by thrusts from the compartment feeder 2, the cross-section of the outlet 8 of the compartment feeder is designed in such a way that it in the rotational direction of the compartment wheel 9 at least initially mainly angularly expands, as indicated in Fig. 2. The idea is based on the fact that the emptying of the compartments alternately coming to the outlet 8 is prolonged in such a way that the emptying starts at the middle of the compartment and transfers uni¬ formly along with the expansion of the outlet toward both ends of the compartments, and before the preceding com¬ partment has totally emptied, the emptying of the next compartment starts so that the material supply to the fluidizing space 3 is as uniform as possible.
In accordance with the preceding embodiment, the side surfaces 10 limiting the angularly expanding portion of the outlet 8 of the compartment feeder are by their cross-section convex toward the outlet, which form even better ensures a uniform material supply.
In the equipment according to Fig. 1, each accelerating nozzle 5 of the counter jet pulverizer is furnished with its own compartment feeder 2 feeding the material to be pulverized and its own fluidizing space 3, into which wor- king gas is potentially supplied from its own pneumatic compressor 6. The manufacturing costs of such a solution are relatively high and the pulverizing occurrence itself is not easily controllable, if abrupt changes occur in the use of the compressors and/or compartment feeders.
A considerably better result is achieved, if the equipment comprises only one compressor 6 and one compartment feeder 2 and a fluidizing space 3, whereby the outlet pipe 11 of the fluidizing space 3 terminates at a bisecting device 12, wherein the material-working-gas suspension divides into two equivalent partial flows entering the pulverizing chamber via their own accelerating nozzles 5. The solution shown in this Fig. 3 ensures that no content and speed differences occur between the material-working-gas showers coming from the different accelerating nozzles 5.
If only a very low working gas pressure is needed for completing the pulverizing process, a more simple and inexpensive pneumatic compressor can be utilized, if the outlet 8 of the compartment feeder 2 and the fluidizing space 3 connected therewith are divided by means of an in¬ termediate wall 13 into two sections of the same size and provided with their own gas inlet pipes 7 and their own material-working-gas-suspension outlet pipes 11 termina¬ ting at the pulverizing chamber 4 via the accelerating nozzle 5. The pneumatic flow is in this case divided for example by means of a simple branch pipe or a bypass mani¬ fold 14 before its entry into the two parts of the fluidi¬ zing space 3, whereby the two material-working-gas- sus¬ pension partial flows can be led directly into their own accelerating nozzles 5, in which case the relatively high counter pressure occurring in the bisecting device can be eliminated. Such a construction is shown in Fig. 4 - 6.
In low-pressure pulverizing, wherein a working-gas pres¬ sure of about max. 2 bar is used, one compartment feeder is enough to maintain a sufficient pulverizing pressure in the equipment. When switching over to pulverization oc¬ curring within the medium pressure range, two compartment feeders 2 arranged on top of each other and a pressure equalization chamber 15 combining them with each other must be used, whereby the pressure over each compartment feeder 2 does not exceed the maximum-pressure-difference duration of the feeder. In this medium-pressure pulveri¬ zing solution, it is sufficient that the outlet of the lo¬ wer compartment feeder 2 is designed so that it equalizes the inventive material flow.

Claims

Claims
1. A feeder of a counter jet pulverizer comprising a fee¬ ding funnel or silo (1) for the material to be pulverized, a compartment feeder (2) arranged in its outlet, the com¬ partments of the compartment wheel (9) of the feeder being by their circumferential dimensions considerably smaller than the diameter of the outlet (8) of the compartment feeder (2), and a fluidizing space (3) arranged on the outlet side of the compartment feeder (2) for achieving in the pulverizing chamber (4) a pressurized material- working-gas suspension to be accelerated via accelerating nozzles (5), c h a r a c t e r i z e d in that the cross- section of the outlet (8) of the compartment feeder (2) in the rotational direction of the compartment wheel (9) ex¬ pands at least initially mainly angularly.
2. A feeder according to Claim 1, c h a r a c t e r i ¬ z e d in that the side surfaces (10) limiting the angu¬ larly expanding portion of the outlet (8) are by their cross-section convex toward the outlet (8) .
3. A feeder according to Claim 1, c h a r a c t e r i ¬ z e d in that each accelerating nozzle (5) of the coun¬ ter jet pulverizer has its own compartment feeder (2) and fluidizing space (3).
4. A feeder according to Claim 1 or 2, c h a r a c t e ¬ r i z e d in that the outlet pipe (11) of the fluidizing space (3) is connected to a bisecting device (12) for di¬ viding the material-working-gas suspension into two equi¬ valent partial flows.
5. A feeder according to Claim 1 or 2, c h a r a c t e ¬ r i z e d in that the outlet (8) of the compartment fee¬ der (2) and the fluidizing space (3) connected therewith are divided by means of an intermediate wall (13) into two sections of the same size and provided with their own gas inlet pipes (7) and their own material-working-gas-suspen¬ sion outlet pipes (11) terminating at the pulverizing chamber (4) via the accelerating nozzle (5).
6. A feeder according to any of the Claims 1 to 5, c a ¬ r a c t e r i z e d in that the feeder is provided with two compartment feeders (2) arranged on top of each other and a pressure equalizing chamber (15) connecting them to each other.
PCT/FI1990/000213 1989-09-15 1990-09-12 Feeder of a counter jet pulverizer WO1991004098A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FI894360A FI894360A (en) 1989-09-15 1989-09-15 MATNINGSANORDNING FOER EN MOTSTRAOLSKVARN.
FI894360 1989-09-15

Publications (1)

Publication Number Publication Date
WO1991004098A1 true WO1991004098A1 (en) 1991-04-04

Family

ID=8528995

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/FI1990/000213 WO1991004098A1 (en) 1989-09-15 1990-09-12 Feeder of a counter jet pulverizer

Country Status (3)

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AU (1) AU6330390A (en)
FI (1) FI894360A (en)
WO (1) WO1991004098A1 (en)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1121631A (en) * 1913-01-16 1914-12-22 Keen Kleener Mfg Company Pulverizing apparatus.
US3876156A (en) * 1971-12-29 1975-04-08 Bayer Ag Method of and apparatus for the jet-pulverisation of fine grained and powdered solids
FI72896B (en) * 1983-03-04 1987-04-30 Finnpulva Ab Oy TRYCKKAMMARKVARNANLAEGGNING.
EP0276742A2 (en) * 1987-01-30 1988-08-03 Bayer Ag Method and device for micronising solids in a jet mill

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1121631A (en) * 1913-01-16 1914-12-22 Keen Kleener Mfg Company Pulverizing apparatus.
US3876156A (en) * 1971-12-29 1975-04-08 Bayer Ag Method of and apparatus for the jet-pulverisation of fine grained and powdered solids
FI72896B (en) * 1983-03-04 1987-04-30 Finnpulva Ab Oy TRYCKKAMMARKVARNANLAEGGNING.
EP0276742A2 (en) * 1987-01-30 1988-08-03 Bayer Ag Method and device for micronising solids in a jet mill

Also Published As

Publication number Publication date
FI894360A0 (en) 1989-09-15
AU6330390A (en) 1991-04-18
FI894360A (en) 1991-03-16

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